KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 14

Some of the metrics are blocked by your
consent settings
Effects of Rotor Eccentricity on Interior Permanent Magnet Motor Performance in Electric Vehicles
(2025-01-01)
Ho, Truc Hoang
;
Chayopitak, Nattapon
;
Pupadubsin, Ruchao
;
Depaiwa, Nattawoot
;
Saito, Takushi
Interior Permanent Magnet (IPM) motors are a popular choice in electric vehicle (EV) powertrains because of their high efficiency, compact size, and controllability. Rotor eccentricity remains a significant challenge because it introduces unbalanced magnetic forces, which increase vibrations, noise, and the risk of premature motor failure. This study investigated the effects of static, dynamic, and mixed eccentricity on the performance of IPM motors and explored how numerical analysis can aid in fault detection during the design and diagnostic phases. This study aims to explore eccentricity fault conditions and their impacts on the motor torque, cogging torque, and magnetic flux density using Finite Element Analysis (FEA) with frequency spectrum analysis. The results show that three types of eccentricity being considered: static, dynamic, and mixed type, produce distinct harmonic signatures that significantly affect the motor's performance characteristics. Specific harmonic ranges are particularly sensitive to different fault types that provide key indicators for early fault detection.
Some of the metrics are blocked by your
consent settings
A Directional Control Auxiliary Thrust System to Increase the Forward Speed of a Quadcopter UAV
(2024-01-01)
Srijun, Chanapan
;
Depaiwa, Nattawoot
This research introduces a method to increase the horizontal speed of a quadcopter UAV using an auxiliary thrust system that can be adjusted in direction. The researcher used thrust vectoring control to align the thrust direction with the unmanned aircraft's longitudinal axis. A method for controlling a device mechanism using a proportional-integral-derivative (PID) control system. Based on the test results, it has been concluded that the Ziegler–Nichols Method in P controller, the Ziegler–Nichols Method in PD controller, and the Trial-and-Error method in PID controller are the most effective methods for maintaining system stability and achieving the setpoint. It took 0.693, 1.441, and 0.563 seconds respectively to reach the desired value. The researcher used computational fluid dynamics and equations of motion to simulate a UAV's speed. The simulation results of using 25% additional thrust while moving at a 2-degree angle showed that the unmanned aerial vehicle's speed increased by 35.3% compared to the unmanned aerial vehicle without the auxiliary thrust system. When the pitch angle was increased to 5 degrees, the speed of the UAV increased by 15.9%. At higher pitch angles of 10 degrees, the UAV's speed increased by 6.86%. Finally, at pitch angles of 15 degrees, the speed of the UAV increased by 4.97%.
Some of the metrics are blocked by your
consent settings
Active Vibration Absorber with Curved Beam Design
(2023-01-01)
Rodyoo, Itsawat
;
Depaiwa, Nattawoot
;
Pinsopon, Unnat
The project aims to design and create an active vibration absorber with a curved beam to reduce vibration. The selected frequency of the vibration generator for this research was limited to 10 to 30 revolutions per minute and is forced to move in one dimension. The vibration generator was controlled by variable resistance with an unbalanced mass that produces centrifugal forces between 14.799 and 133.189 newtons at frequencies of 10 and 30 revolutions per minute, respectively. To control the natural frequency of the active vibration absorber, the microcontroller STM32F103C8T6-Black Pill and absorption frequency was used with a set of controlling criteria that help to adjust a spring's stiffness. The spring was designed as a curve beam so that the absorber would be small and easy to use while having a wider working range and reacting quicker to a change in load. To reduce system vibration, the spring stiffness was properly adjusted by changing the curve beam's length by changing the locker arm's position using a rotating motor. The feedback control system, meanwhile, was used to adjust the motor's position through variable resistance and then calculate a feedback error to the corrected position, resulting in a natural frequency of the absorber that was similar to the system's vibration frequency. Moreover, the relationship between spring stiffness and curve beam length was also investigated to obtain the function of locker arm position and specify the angle of the motor's shaft. Experiments to test the correctness of theory and method were also conducted. Prior to the experiment, the vibration absorber's efficiency was assessed using ADAMS motion simulation software. The efficiency as a percentage drop in the main system vibration amplitude was calculated while the vibration absorber was mounted. At an operating frequency of 15 Hz, which is close to the natural frequency of the main system, the test results show that the vibration can be reduced by up to 65.49 percent. However, based on the experiment's results, the efficiency was defined as a percentage of a reduction in vibration amplitude in the primary system, both with and without an active absorber. The most efficiency as a percentage drop in the main system vibration amplitude was 34.917%, while the least efficient was 7.711%. It was concluded that the active vibration absorber design with the curved beam can reduce vibration, and while the results were not the best, they were enough to warrant the commencement of future studies.
Some of the metrics are blocked by your
consent settings
Development and Design Structure and Mechanism of Sugarcane Harvester with Leaf Pruning Machine
(2023-01-01)
Jukgoljun, Wisawa
;
Moonumca, Pisan
;
Depaiwa, Nattawoot
The purpose of this research is to design, develop, and analyze the damaged structure and mechanism of sugarcane harvesters, then find suitable materials to use for sugarcane harvesters that respond to the needs of farmers. Nowadays, sugarcane harvesters are quite expensive. Consequently, most people prefer to harvest sugarcane by burning the leaves before cutting, which causes air pollution. The authors decided to start designing and developing the whole sugarcane cutting machine. The leaves and stems can be cut with a machine that only uses power from the power take-off shaft. The authors also analyzed the properties that affected the experiment's results. It can be concluded that in terms of the material, the properties should be considered as follows: The tensile value should be greater than 3700 psi and the shear strength should be at least 10000 psi to prevent material damage from turning and pruning leaves. Hardness, meanwhile, should be lower than Rockwell M110, so the material will not cause cane damage. The Flexural Modulus of Elasticity value is about 450,000 psi. The harvesters should be connected to a tractor that has 67 horsepower or more. The whole structure works as a whole system, with no parts broken during the 48-hour trial. The machine was optimally operated using 540 rpm. of power from the power shaft. The speed of the base-cutting, using the finish-made cutter, was 337.5 rpm. The nylon lawn trimmer is the best leaf pruning tool. It is because its softness did not cause the sugarcane any damage while having no tangle in its use, which led to an improvement of the machines. Results showed that harvesters can harvest up to 300 sugarcanes per hour using this machine.
Some of the metrics are blocked by your
consent settings
Experimental investigation of the influence of ethanol and biodiesel on common rail direct injection diesel Engine's combustion and emission characteristics
(2022-11-01)
Wai, Phyo
;
Kanokkhanarat, Phobkrit
;
Oh, Ban Seok
;
Wongpattharaworakul, Veerayut
;
Depaiwa, Nattawoot
This study aims to characterize the effect of oxygenated biofuels in diesel engine combustion, thermal efficiency, and emission by blending different percentages of ethanol and biodiesel with fossil fuel derived diesel. In this research, 5% and 10% by weight of bioethanol were added to commercial B10 (10% biodiesel and 90% diesel), B20 (20% biodiesel and 80% diesel) and B100 (100% biodiesel) and experimented on using a 3 L four-cylinder common rail diesel engine. The experiment was performed under three engine speeds of 1000 rpm, 1500 rpm, and 2000 rpm with three constant engine torques of 56 Nm, 84 Nm, and 140 Nm. The results show that ethanol-biodiesel-diesel ternary blended fuels are higher in premixed combustion pressure and net heat release rate (NHRR) peaks. The cumulative heat release of ethanol blended fuels is also higher for ethanol blended fuels. The fuel consumption increased with the ethanol and biodiesel percentage in the blended fuels due to the lower heating value while the brake thermal efficiency did not decrease. It was clearly observed that the particle emission could be reduced by more than 50% when ethanol and biodiesel percentage increased.
Some of the metrics are blocked by your
consent settings
Impact of Driving Behavior on Power Consumption of Electric Bus: A Case Study on Rama IX Bridge
(2022-01-01)
Phyo, Lwin Yamon
;
Depaiwa, Nattawoot
;
Yamakita, Masaki
;
Kerdsup, Burin
;
Masomtob, Manop
Recently, the influence of the bus transportation system in Thailand has become the most critical impact on our surroundings. Government of Thailand has initiated the projects to replace internal combustion engine buses with net zero-emission. However, there are the problems of power consumption in battery electric buses, especially on climbing resistance which is a major impact on the power demand and recuperation. This paper aims to investigate the impact of driving behavior on power consumption of electric buses. Many scenarios have been created to study such behavior. Also, driving across Rama IX bridge which is the critical scenario on the performance of electric buses in Thailand has been evaluated.
Some of the metrics are blocked by your
consent settings
Influence of ethanol biodiesel blends on a diesel engine's efficiency and exhaust emission characteristics
(2022-01-01)
Kanokkhanarat, Phobkrit
;
Karin, Preechar
;
Depaiwa, Nattawoot
;
Wongpattharaworakul, Veerayut
;
Srisurangkul, Chadchai
The harm caused by polluted air occurs from dust, smoke, or soot. One of the main causes of pollutions is exhaust emission that comes from diesel engines of cars, trucks, buses, heavy machines, or generators for industrial because their thermal efficiency, torque, and performance are higher than the other engines. To reduce the emission from diesel engines, the fuel substitute for biodiesel which is made from based palm oil is one of the alternatives to use. So, the purpose of this paper is an experimental investigation of the engine performance, combustion characteristics, and smoke intensity of commercial biodiesel fuels (B10 and B20), pure biodiesel fuel (B100), and pure biodiesel blended with ethanol fuels (B100E5 and B100E10), which were performed at various loads (56, 84, 112, and 140Nm) and conducted at constant engine speeds (1000, 1500, and 2000 rpm). The experimental results show that pure biodiesel fuel (B100) and pure biodiesel blended with ethanol fuels (B100E5 and B100E10) have engine performance and combustion characteristics similar to commercial biodiesel fuels (B10 and B20). However, pure biodiesel fuels (B100) and pure biodiesel blended with ethanol fuels (B100E5 and B100E10) can reduce the emissions as the smoke intensity from commercial biodiesel (B10 and B20) is more than 50%.
Some of the metrics are blocked by your
consent settings
Investigation of the Impact Bioethanol Blends into Biodiesel on Combustion Characteristics, Engine Performance, and Emissions of Diesel Engine
(2022-01-01)
Kanokkhanarat, Phobkrit
;
Depaiwa, Nattawoot
;
Karin, Preechar
;
Wongpattharaworakul, Veerayut
;
Srisurangkul, Chadchai
Emissions from a diesel engine are dangerous to the environment and human health. Substitutable fuels from a renewable source are one of the alternatives to reduce emissions. Neat biodiesel from based palm oil (B100) can reduce emissions from higher oxygen content to be more complete combustion. The disadvantage of neat biodiesel is lower thermal efficiency from an advancement ignition. To improve this problem, adding bioethanol produced from agriculture products into neat biodiesel by weight ratio as B100E5 (95% B100 with 5% bioethanol) and B100E10 (90% B100 with 10% bioethanol). Hence, the focus of this research is to examine the combustion and emission characteristics, including engine performance, of bioethanol blends into neat biodiesel fuels (B100E5 and B100E10) compared with neat biodiesel (B100). All samples were tested at an engine load of 140 NM with constant engine speeds of 1000, 1500, and 2000 RPM on a diesel engine. The results of bioethanol blends into biodiesel fuels indicate that the pressure in the combustion cylinder and rate of heat release increase with increasing percentages of bioethanol. B100E10 shows the highest brake thermal efficiency. The smoke intensity of bioethanol blends into biodiesel fuels is reduced by more than 50% when compared to neat biodiesel fuel, and higher NOx emission from higher oxygen content in the fuels.
Some of the metrics are blocked by your
consent settings
Thermal performance in a tubular heat exchanger with deltawinglets
(2018-08-14)
Tongyote, Pattarapan
;
Promvonge, Pongjet
;
Depaiwa, Nattawoot
;
Jedsadaratanachai, Withada
The paper presents an experimental heat transfer enhancement study in a tubular heat exchanger fitted with delta-winglets. The experimental work was conducted by varying the airflow rate in the test tube having a constant wall heat-flux for turbulent regime, Reynolds number (Re) from 5200 to 23,000. Effects of three pitch ratios (PR=P/D=1.5, 2.0 and 3.0) and two attack angles, α = 45° and 60°, of the winglets at a single blockage ratio (BR=b/D = 0.15) on thermal characteristics are examined. The experimental results show that the winglet-inserted tube yields, respectively, the heat transfer, friction factor and thermal performance in the form of TEF around 1.99-4.08, 4.9-14.3 times higher than the plain tube and 0.85-1.85, depending on the operating condition.
Some of the metrics are blocked by your
consent settings
The force tracking control of electro-hydraulic system based on particle swarm optimization
(2016-01-01)
Moonumca, Pisan
;
Depaiwa, Nattawoot
This paper presents the optimal gains of backstepping controller by using the particle swam optimization technique. The mathematical model is developed by Newton’s second law, compressible fluid flow and flow rates of valve. The control law is formulated by employing a Control Lyapunov Function. The core feature of this paper is the combination of the backstepping and particle swam optimization for optimal performance of controller. The controller gains are determined in automatic selection gains by minimizing the integral of time multiplied by absolute error function on step input. The fitness value can be guaranteed to the convergence of controller gains. The implementations are separated into two cases which are the real and estimated state feedbacks. The experiment has illustrated to find optimal controller gains. The results are also compared with the tracking response of real and estimated state measures in step and square signal. The results show a better tracking performance by using the strong particle swarm optimization (PSO) algorithm.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results